Vehicles, such as cars, are presently equipped with occupant restraining seat belts installed by the manufacturers of the cars. While such seat belts are adequate for restraining adults in the event of a sudden stop, collision or other emergency, most are inadequate for protecting small children and infants. As a result, a variety of specially designed child restraint devices have been designed and developed and are in widespread use today. Child car seats are indeed required by all states as a matter of law for use with infants and children who are of such size that a standard vehicle seat belt does not afford adequate protection. Conventional child car seats typically utilize the vehicle seat belt provided by the vehicle manufacturer to secure the child seat to the vehicle.
Most vehicles today come equipped with a three-point seat belt system, which is either formed from a lap belt and a shoulder harness joined together in a non-movable latch plate or one continuous belt having a movable or dropping latch plate separating the lap belt portion from the shoulder harness portion. In either configuration, the latch plate is coupled together at one end for releasable securement by the wearer to a buckle at a first fixed point on the car seat adjacent the wearer. The lower belt is the horizontal lap belt extending over the wearer's lap to an adjacent second fixed point. The second or shoulder belt extends transversely from the buckle or anchor, angling upwardly across the wearer's chest and shoulder, to an elevated fixed third point.
To promote compatibility between child restraint systems and vehicle seats and seat belts, the SAE (Society of Automotive Engineers) publishes design guidelines which it provides to vehicle manufacturers as well as child restraint system ("CRS") manufacturers. For example, SAE Standard J1819, directed to securing child restraint systems in motor vehicles, is designed to ensure that a tight interface between a CRS and a vehicle seat exists regardless of the position of the seat belt anchor. This standard recommends to vehicle manufacturers that the buckle-latch plate assembled length shall be such that the end of the latch plate is within a circular segment having a radius of eight inches (20 cm) from the seat bight (the intersection of the seat back and the seat bottom or seat pan) in order to minimize the forward movement of a fixture resembling a CRS. The seat belt anchor generally consists of a stiff shank or piece of webbing having a buckle at its free end. The latch plate is located on the seat belt and when fastened, joins the lap belt and/or shoulder harness to the seat belt anchor.
Standard J1819 further recommends to CRS manufacturers that the CRS have an entry position (for the vehicle seat belt assembly) which is at least eight inches (20 cm) from the bight of the seat when the CRS is installed. This eight inch (20 cm) radius ensures that the vehicle buckle assembly would not rest on the entry point of the CRS. Unfortunately, SAE Standard J1819 is voluntary and there are a number of vehicles and seating positions that are not compatible with conventional CRSs due to high vehicle buckle heights and/or forward anchor positions.
In many vehicles, the buckle or anchor is indeed located very near the seat bight, and thus can accommodate a conventional car seat having a belt pathway located either directly in back of or underneath the child. See, for example, U.S. Design Pat. No. 311,281; U.S. Design Pat. No. 286,470 and U.S. Pat. No. 4,886,315. With vehicles having this type of seat belt configuration, when the vehicle seat belt is threaded through a conventional car seat and fastened to the buckle or anchor, the car seat is properly positioned firmly against the vehicle seat bottom and seat back giving a secure retention.
In some newer model vehicles, however, the buckle or anchor is located away from the seat bight, generally more forward and/or higher on the seat. Also, some vehicles have the anchor or buckle extending upward from a shaft on the floor or side of the seat. While this new configuration may provide greater comfort for adult users of the seat belt, it is highly incompatible with the belt pathways in conventional child car seats. When used with a conventional child car seat, a two- or three-point seat belt system with a forward anchor configuration presents an unacceptable situation since the seat belt cannot fit the child car seat snugly to the vehicle. In other words, the forward anchor position allows a moderate degree of fore-aft translation between the vehicle seat back and a car seat having conventional belt pathways. Therefore, there exists a need for a child car seat equipped with a belt pathway to properly accommodate a variety of different seat belt configurations, including forward- and/or high-anchor configurations.
Moreover, a number of vehicles equipped with a three-point seat belt system incorporate a dropping or movable latch plate on the belt. This movable latch plate separates the lap belt portion from the shoulder harness portion of the seat belt and provides the necessary connection point to the buckle. When using a child car seat with a seat belt system incorporating a dropping latch plate and a shoulder reel equipped with an ELR (emergency locking retractor), the seat belt system cannot securely fasten the car seat to the vehicle and it has been heretofore necessary to use an additional locking clip to isolate the lap portion of the belt from the shoulder belt reel and ensure a snug fit between the child seat and the vehicle. The locking clip essentially locks the shoulder harness portion to the lap belt portion of the seat belt prior to engaging the child car seat to avoid any excess movement or play in the lap belt portion of the vehicle seat belt. Although critical, these clips are difficult to position and use effectively. Therefore, there exists a need to provide an improved system for securely fastening a child car seat to a vehicle equipped with ELR and having a three-point seat belt system with a dropping or movable latch plate.
Convertible child car seats, i.e. seats capable of being used in a rear-facing or forward facing orientation, are well known in the field. Depending on the desired orientation, the vehicle seat belt must generally be threaded through the child car seat in a different way to securely fasten the seat to the vehicle. See, for example, Kain, U.S. Pat. No. 4,764,999. The improper installation of a child car seat in a vehicle, in either orientation, is a very real possibility. Therefore, it would be advantageous to have a convertible child car seat which has more clearly identified and well-marked vehicle seat belt pathways through which a vehicle seat belt is passed to ensure a proper securement.
With respect to convertible child seats, it is a matter of law in all states that a child weighing less than 20 pounds (or generally one year of age) must be placed in a child car seat secured in a vehicle in a rear-facing, more reclined direction until their body develops sufficiently and can withstand the forces involved in a crash when forward facing. Once the child weighs more than 20 pounds, the child car seat can be placed in the vehicle in a forward-facing, more upright position. While children obviously grow at different rates, smaller children generally occupy the child car seat in its rear-facing position. Similarly, older and generally larger children usually occupy the child car seat in its forward-facing position. Since it is not economical to buy a new car seat every few months or years as the child grows, many manufacturers incorporate one or more adjustment mechanisms to permit the child seat to accommodate children of different sizes, as well as both orientations.
Since infants generally occupy the car seat in its rear-facing position, the harness adjustments necessary for an infant (i.e., a child under 20 pounds or one year of age) generally correspond to the rear-facing position. Similarly, toddlers generally occupy the seat in its forward-facing position, and thus the larger harness adjustments necessary for a toddler generally correspond to the forward-facing position. With conventional convertible car seats, the seat belt path recommended by the manufacturer may be very complex. Moreover, users may lose or not even bother to read the installation instructions, thereby resulting in an improperly installed car seat. It would be advantageous to have a convertible car seat that had easily identifiable and distinguishable belt pathways. It would also be advantageous to have a convertible car seat that had easily identifiable corresponding harness adjustments.